FIG. 17 shows a sectional view of an aluminum electrolytic capacitor, i.e. one of conventional electronic components. FIG. 18 shows a perspective view of a lead-wire to be used in the aluminum electrolytic capacitor. FIG. 19 shows a sectional view of the lead-wire.
As shown in FIG. 17, the aluminum electrolytic capacitor is formed of capacitor element 6, which works as a functional element, lead-wire 1, housing 7, and sealing member 8. Lead-wire 1 is led out of capacitor element 6, and housing 7 shaped like a cylinder with a bottom accommodates capacitor element 6. Sealing member 8 is provided with through-holes 8a through which lead-wires 1 run. Sealing member 8 is placed at the opening of housing 7, and it is drawn at drawn section 7a provided on the outer wall of housing 7, whereby the opening of housing 7 is sealed.
As shown in FIG. 18, lead-wire 1 is formed of led-out electrode 2 made of aluminum round bar, cap 4, and flat section 2e. As shown in FIG. 19, cap 4 is put over first end 2a of led-out electrode 2. Flat section 2e is formed by pressing a second end of led-out electrode 2 into a flat shape, and is coupled to capacitor element 6. Cap 4 covering first end 2a works as a terminal to be coupled to circuit board 10, and it is made of the material ready to be soldered.
The aluminum electrolytic capacitor discussed above uses lead-wire 1 of which cap 4 covering first end 2a works as a terminal, so that malformations at a junction between first end 2a and the terminal can be reduced comparing with the malformations occurring when first end 2a is directly melted to a wire-like terminal. Quality of the aluminum electrolytic capacitor thus can be controlled with ease, and the highly reliable capacitor stable in bonding quality can be thus obtained. The aluminum electrolytic capacitor discussed above is disclosed in, e.g. patent literature 1.
However, in the case of fitting cap 4 to first end 2a by, e.g. press-fitting, for covering end 2a, cap 4 sometimes encounters deformation in appearance, or burrs are sometimes produced at the end of the opening of housing 7. When lead-wire 1 is inserted into through-hole 8a of sealing member 8, the deformation or the burr may incur a gap between the outer wall of cap 4 and the inner wall of through-hole 8a. Burrs produced on lead-wire 1 scratch the inner wall of through-hole 8a, so that the electrolyte tends to leak. The sealing reliability may be thus lowered. On top of that, the insertion of lead-wire 1 into through-hole 8a causes the burrs produced on lead-wire 1 to come off to capacitor element 6, and may invite a short.
Patent Literature 1: Japanese Utility Model Publication No. S63-178318